This project aims at increasing knowledge of the human genetics map, by collecting collaboratively information with new (and old) markers on a selected sample of pedigrees and nuclear families. New markers are provided by DNA probes, in part random and in part corresponding to known genes; and also by monoclonal antibodies against specific proteins. Among classes of genes that are particularly investigated are: immunoglobulin heavy chain genes (and proteins); leukocyte membrane antigens; nuclear genes determining mitochondrial proteins, and several others. Blood samples are being collected locally, and also in cooperation with other laboratories which already have collected, or are interested in collecting, blood samples from families that are satisfactory for linkage purposes, and these are or will be typed for classical genetic markers. All information will be centralized on a computer and analyzed for gene frequency segregation, linkage and other aspects of genetic interest. Comparisons between genetic, cytological and deletion maps will be carried out. It is expected that the project will continue producing new markers of interest for a variety of purposes, ranging from the study of the human genetic map, to those of association with diseases and of population genetics.